Childhood disintegrative disorder (CDD) is a rare pervasive developmental disorder, which is often misdiagnosed as schizophrenia, probably due to the resultant severe social impairment and withdrawn behaviour with stereotypys that could be mistaken for psychosis. We report a case of CDD that was misdiagnosed by a psychiatrist as childhood-onset schizophrenia and treated with high doses of antipsychotics. The patient did not show any improvement. This highlights ethical issues that arise from treatment modalities, with polypharmacy being the biggest culprit, and also points to the need to continue medical education at the level of primary health services and among practising rural doctors where tertiary centres with child guidance facilities and a multidisciplinary team are not available.